Speaking-telephone transmitter



(No Model.) 2 Sheets-Sheet 1.

T. J. PERR'IN.

SPEAKING TELEPHONE TRANSMITTER- No. 307,728. 7 Patented Nov. 4, 1884..

ITNESSES INVENTOR Than asul l'errin @1 By his flttorneys i N. PETERS. PhoIo-Mhogmplm. Washington. 0,6.

2 H e e h S S t e e h s 2 N I R D E P l T a d 0 M 0 W SPEAKING TELEPHONE TRANSMITTER Patented Nov. 4,1884.

INVENTOE Thomas .T. lerrin flaw/(Q WITNESSES By his Attorgys N. PETERS. mom-ulhu lmr. Wilih ngkim 01C.

lharrnn @rarns Parent Orrrcn.

THOMAS J. PERRIN, OF NEYV YORK, N. Y., ASSIGNOR TO THE NATIONAL IMPROVED TELEPHONE COMPANY, OF NEIV ORLEANS, LOUISIANA.

SPEAKING TELEPHONE TRANSMITTER.

EPEQIPICATION forming part of Letters Patent No. 307,728, dated November 4, 1884:.

Application filed September 18, 1884. (No model.)

To aZZ whom it may concern.-

Be it known that I, THOMAS J. PERRIN, of the city, county, and State of New York, have invented certain new and useful Improvements in SpeakingTelephone Transmitters, of which the following is a specification.

My invention relates to that class of transmitting instruments in which the electrical condition of the main line is caused by variations of resistance in a transmitting-circuit, which variations are caused by the vibration of the diaphragm.

The object of the first part of my invention is in a practical and efficient manner to combine in a single instrument the effects of several independent primary transmitting-circuits upon a single main line; and, as collateral to this feature of thcinvention,the invention consists in certain improvements in structure and organization, which are fully disclosed below.

The object of the next part of my invention is to provide an improved adjustment or control of the contacts or electrodes in that class of instruments in which the pressure of the electrodes against each other is maintained by the attracting force of a magnet, either a permanent or an electro magnet.

The details of this part of my invention are also fully described.-

In the accompanying drawings, Figure 1 is a transverse central section through the instrument on the line 1 1 of Fig. 2. Fig. 2 is a section on the line 2 2 of Fig. 1, looking in the direction of the arrow, and Fig. 3 is adia gram view illustrating the circuit-connections and contacts.

A is the case of the telephone, which is provided with a suitable swinging door, B, which is provided with a suitable mouth-piece, B. On the interior of the door a diaphragm baseplate, B", is preferably secured, and the dia phragm O is held in place over the central opening in said plate opposite the mouth-piece by retaining fingers or buttons b, in theordinary way.

Upon the inner face of the plate B are secured four groups of apparatus, D E F G, and upon the center of the diaphragm are socured four insulated contacts, a e f g-one for each group of apparatus mentioned. It will be sufiicient to describe one group,as the other three are indentical in construction and operation. A bracket or frame, H, is secured upon the plate B by clamping-screws, which pass through elongated slots in the bracket, so as to permit of its adjustment. The end of the bracket farthest from the plate is turned up at right angles, so as to form a standard, H, through which an extension, H, of the core of an electromagnet, I, passes. The electro-magnet is supported at its front end in a circular socket in a vertical standard or flange, which rises from the bracket H between its point of attachment with the plate 13 and its end H. The core of the electromagnet is endwise movable within its coil, and is normally thrust forward by a coilspring, H", and its position is regulated by a nut, H on the end of the extension H of the core. An extension, K, of the bracket or frame H projects from its point of attachment with the plate B toward the center of the diaphragm. This extension carries ordinary well-known delicate pivoting devices, K, which support a pivoted lever, L. One end of this lever carries a contact-button, Z, which bears against one of the insulated contact-buttonssay-Z-secured on the diaphragm. The opposite end of the lever is somewhat enlarged,and constitutes an armature for the electro-magnet I. The contact-buttons land (Z can be brought into suitable opposite position by the adjustment of theframc II toward or from the center of the diaphragm. In operation, as is hereinafter described, the attraction of the magnet I on the ar1nature-lever L maintains the contact between the buttons Z d, and the coil of the magnet I is included in a primary transmitting-circuit. of which the pair of buttons Z d constitute the electrodes.

I will here remark that I am aware that, broadly, the employment of an electromagnet to maintain contact between the electrodes or buttons of a transmittingcircuit is not new, although the special organization of apparatus and relative arrangement of parts which I have already described are novel, and constitute a very convenient and efficient structure.

, field of its regulating-magnet and separate the contacts.

In instruments not constructed according to my present invention, when the armature is so thrown out of the field and the contacts separated, the armature swinging upon its pivot is liable to vibrate and rebound one or more times from the diaphragm before'settling into a normal working condition. This seriously mars the operation of the instrument and injures the contact-surfaces. To-carry out this branch of my invention I prefer to employ the peculiar devices illustrated in the drawings, or devices substantially similar to them, although vother ways of accomplishing the same result may doubtless be devised. A delicate plate-spring, M, is secured upon the base of thebracket or frame II, so that it can be brought to bear upon the armature-lever andtend to move it toward the pole of the magnet. The spring is adjusted by means of a screw, m. The required adjustment of the contacts and of the spring M can readily be obtained by adjusting the core of the magnet to or from the armature-lever until the force of attraction brings the buttons Z d into proper contact. The spring M is also adjusted so as barely to touch very gently the armature-lever. \Vhen thus adjusted, any tendency of the armature to move out of the field of its magnet is prevented, and any sudden jar or shock to the instrument will not cause the separation of the electrodes. As the diaphragm is caused to vibrate by sounds uttered into the mouth-piece, variations of contact occur between the buttons Z d, which are in the transmitting-circuit, and cause, by means of an'inductioircoil, the proper electrical condition on the main line, as is'well understood. The magnet I, the coil of which is included in this primary transmitting-circuit, acts upon the lever L proportionately to the variations of current in its coil, and produces a perfect condition of contact between the buttons, as is well understood.

All of the apparatus may readily be reached for adjustment by swinging open the door of the instrument, on the interior of which all the parts are carried.

The construction and operation, as before remarked, of the four groups of apparatus D E F G are precisely similar. So far, however, as the feature of my invention already de scribed is concerned, but one pair of contacts and one primary circuit need only be employed. In adjusting the instrument one primary circuit only is closed, and the instru-.

ment is then brought into proper adjustment for transmission. This circuit is then opened and another circuit is closed and similarly adjusted, and so on.

Intelephoning long distances and under unfavorable conditions the ordinary primary circuit, equipped with the ordinary transmit ting-battery, does not produce a suffieient electro-motive force in the secondary of the induction-coil, and there are certain objections to increasing the amount of battery-power in the primary circuit of the induction-coil.

In the organization shown the four pairs of contact-buttons Zd Z Z7" lg are each included in an independent primary circuit,and all four of these primary circuits act upon a common secondary,which goes to line. I am aware,however, that broadly,in a transmitting-telephone, the use of more than one primary circnitto act upon a single secondary is old, and my invention does not contemplate such broad ground.

In the diagram view, Fig. 3, the magnets I and the four pairs of contacts Id Z6 ZfZg and their separate primary circuits d cf g are clearly shown. Instead of four separate induction-coils, however, Iemploy a single compound induction-coil, O, which is wound in the following manner: Upon the core 0 is first wound a layer of the primary circuit 9,

and over that is wonndalayer of the continuous secondary circuit 8. I now prefer to cover this layer of the secondary coil with paper, and slip over it a tubular soft-iron sheath or cover, 1). Over this tnbeis now wound alayer of the primary circuitf, and over this a second layer of the continuous secondary circuit 8. Over this layer a coating of paper is preferably placed,'and a second iron tube, 19, is preferably slipped over it. A layer of the third primary circuit, 6, is now wound on the tube 1), and over that a third layer of the continuous secondary circuit sis wound. Aeovering of paper is passed over this coil, and a third iron tube, 1), is slipped over it; and on this last tube the fourth primary circuit, (1, is wound, and over it the last winding of the continuous secondary circuit 8. As the transmitting-diaphragm, therefore, vibrates in response to sound-waves which strike upon it, corresponding variations in resistance in the four independent primary transmitting-circuits are simultaneously produced, and these variations in resistance simultaneously act upon the single secondary line. Y

I haveshown four primary circuits. It is not essential, however, so far as this feature of my invention is concerned, whether four only be employed or whether as many as four be employed; and in Letters Patent No. 308,948, granted to me August 19, 1884, Ihavc shown an organization in which but two primaries wound into a compound induction-coil in exactly thesame manner ashereinillustrated and described are employed.

\Vhile the details of construction herein illustrated and described are those deemed by me best adapted for the adjustment of the parts and the accurate transmission of articulate speech, they may of course be largely varied without departing from the principles of my invention.

it am aware that it is old to maintain the electrodes ofa transmitting-telephone in con.- tact by meansof an elcctromagnet included in the primary transmittingcircuit, which acts on a pivoted arm carrying one of said electrodes, and I do not claim such organization, broadly.

No claim is made herein, broadly, to the inductioncoil shown and described, as that constitutes the subject-matter of another application to be filed by me. Nor is any claim made herein, broadly, to the combination of a transmitting diaphragm, two or more contact-buttons mounted on or controlled by said diaphragm, a corresponding electrode or button for eachinsulated electrode on the diaphragm,and an independent primary transmitting-circuit for each pair of said electrodes, as such subjects-matter are elaimedin my original application,No.121,419, filedFebruary 20, 1884, of which this case is a division.

I claim as my invention- 1. The combination, substantially as set forth, of a transmittirig-diaphragm, the electrodes of a transmitting-circuit,between which variations of contact are caused by the vibrations of the diaphragm, a lever or electrodesupport which maintains the electrodes in contact, a magnet acting upon said levertomaintain contact between the electrodes, and a spring or yielding controlling device which bears on said lever and tends normally to prevent it from leaving the field of its magnet.

2. The combination, substantially as set forth, of a diaphragm, a transmitt-ing-cireuit, the electrodes or contacts of said circuit, be-

tween which variations of pressure are caused by the vibrations of the diaphragm, a leveror electrode-support which maintains the electrodes in contact, an electromagnet the helix of which is included in said primary circuit,

and a spring or yielding device which bears on said lever and tends to prevent the leverfrom leaving the field of its magnet.

3. The combination, substantially as set forth, of a diaphragm, a transmitting circuit,

the contacts or electrodes of said circuit, be-

tween which variations of pressure are caused by the vibrations of the diaphragm, alever or electrode-support which maintains the electrodes in contact, a magnet acting upon said lever to maintain contact between said elec trodes, means for adjusting the magnet to or from said support, a spring or yielding de vice which bears on said lever and keeps it in the field of its magnet, and means for adjusting said spring device.

a. The combination, substantially as set forth, of the casing, the swinging door, the bracket or frame H, secured upon the inner face of the door, the pivoted armature or lcver mounted in said frame, the contacts or buttons, one secured on the diaphragm and the other on the armature-lever, the magnet mounted in said frame or bracket, and means for adjusting it relatively to the armaturelever.

5. The combination, substantially as set forth, of the casing, the swinging door, the diaphragm mounted in the door, a frame or bracket, H,secured upon the inner face of the door, a pivoted arm or lever mounted in said bracket, the contacts or electrodes, carried one by said lever and the other by the diaphragm, and means for adjusting the frame readily to or from the center of thediaphragm.

6. The combination, substantially as set forth, .of a transmitting diaphragm, two or more independent primary circuits, their electrodes, and a compound induction-coil,wound first with one primary cirenit,then with a por tion of the secondary line, then with another primary circuit, and then with another portion of the secondary line, and so on, substantially as described.

7. The combination, substantially as set forth, of a transmittingdiaphragm, two or more independent primary circuits, their electrodes, and a compound induction-coil formed as follows: first, of a core on which one primary wire is wound, over which primary a layer of the continuous secondary wine is wound, then of a tubular iron sheath or cover on which is wound the second primary circuit and a second layer of the continuous second ary line, and so on.

S. The combination, substantially as set forth, of a transmitting-diaphragm, two or more independent insulated electrodes controlled by said diaphragi'n, a corresponding contact or button for each of said electrodes, an independent primary circuit for each pair of said electrodes, and a single secondary line on which all of the primary circuits :act.

In testimony whereof I have hereunto sulr scribed my name.

THOMAS J PERRIN Witnesses:

J N0. It. J unmv, JOHN J UDEN. 

